This invention relates to a fixing unit and an image forming apparatus for use in, for example, an electrophotographic color copy machine or a color printer.
In a fixing unit used in an electrophotographic color copy machine or a color printer, a fixing roller is coated with a great amount of silicone oil in order to prevent the toner from attaching thereto. Although there are various types of methods for the coating of silicone oil, the following method is generally used:
First, silicone oil is pumped from an oil tank by an oil pump, and dripped onto oil coating felt. The oil then permeates the felt and sticks to an oil supply roller, where the oil is made to a predetermined thickness by a regulating blade. After that, it is applied to a fixing roller via a coating roller.
The oil, made to come off the oil supply roller by the blade, drips into an oil pan and returns to the oil tank to be used again. After the oil tank becomes empty, it is replenished with new oil.
In the conventional case, however, supplementary oil is supplied into the oil tank through a filling port provided therein. Accordingly, it is highly possible that the oil will spill from the tank and soil its peripheral components.
This being so, the oil replenishing work is liable to be shunned by a general user and is usually performed by a professional maintenance worker. When the professional maintenance worker does it, the downtime of a printer, a copy machine, etc. becomes too long to ignore.
Also, even where the professional maintenance worker exchanges a dirty oil-soaked felt with a new one, oil may spill from the felt when removed since a great amount of oil is absorbed in it.
In addition, since oil remains in the oil pan, it will spill therefrom if the fixing unit inclines while, for example, the unit is moved.